As a typical example exhibiting semiconductor properties, Group 14 elements such as silicon and germanium are represented. Particularly, silicon has been utilized in almost all of the semiconductor devices because of its wide availability, ease of processing, excellent semiconductor properties, and ease of controlling the properties. Similar to silicon, an oxide exemplified by an oxide of a Group 13 element such as indium and gallium also shows semiconductor properties and can be used in a semiconductor element such as a transistor. As exemplarily disclosed in Japanese patent application publication No. 2015-225104, International publication No. WO2015/031037, and United States patent application publication 2010/0182223, a semiconductor device in which both a transistor having a silicon-including semiconductor (hereinafter, referred to as a silicon semiconductor) and a transistor having an oxide semiconductor are incorporated has been developed.